Additional things to consider...
If the car is burning oil (blue smoke = oil burning), the plugs are getting
fouled. Plugs would foul whether source is guides, rings, or PVC
diaphragm. ' Hope it's the diaphragm, BTW!
Another source of rough running not mentioned so far - with year's of wear,
the wire grounding the breaker plate to the distributer body can break off
where it attaches to the plate. The car will still "run" as the breaker
plate does ground through it's bearing - but it is an intermittent ground
and the car will run very rough and backfire a lot.
Also, how about lateral "wobble" movement in the distributer spindle? Last
time this happened to me (DPO failed to oil the spindle) I discovered
enough wobble in the spindle to open and close the points! I drove it 600
miles home this way. Some folks will argue the fix it to go to electronic
ignition as these systems are not sensitive to lateral play in the spindle.
True, but for less money, you can buy a rebuilt distributor. I've had
traumatic failure three times with electronic ignitions - never with points.
While I would think timing chain failure would be terminal, perhaps greater
minds on the list will confirm/deny the possibility of a timing chain
tensioner failure - causing lots of slop in the cam timing. I would think
a tensioner failure would lead relatively shortly to chain failure.
Allen
>From: richard <juju34@texoma.net>
>
>things to look at...
>
>coil breaking down,
>
>fuel pressure, lucas fule pump
>
>air/vacuum leaks
>
>cracked distcap/rotor, leaking plugh wires[ high tension leads] fouled
>plugs
>
>
>to thick/or no oil in carb slides
>
>one carb float hung...etc
>
>carb linkage
>
>pvc diaphram...althought this should cause smoking[ as in oil burning ],
>on top of the intake manifold between the carbs...remove the metal keepr
>spring wire, prise up the cover remove and clean the rubber, hold up to
>a bright light and look for daykight , daylight = replacement
>
>since you mentioned having to set timing freguently , recently, have you
>checked the points...the fibre tab that rubs the cam , can wear , and
>faster with out the dab of grease it shold have,,,[if you running stock
>ignition]
>
>brit cars will make you a deep thinker...so will italian, german, etc
>
>richard, brit/euro auto and bike restorer
>'67 bgt
>70 dhc
>other brit and euro marquess auto and bikes
>
>Neil Cotty wrote:
>>
>> Tom,
>>
>> > Car was running rough the whole way back, about 45 miles.
>> > I have had to reset timing numerous times in the last 2-3 weeks,
>> > and I think this is unusual.
>>
>
******************************************
Allen H. Bachelder =iii=<
Sinking Creek Home for Wayward MGs
49 YT, 57 ZB, 58 ZB, 65 B, 67 BGT, 73 B, 73BGT, 76 B, &...
New Castle, VA 24127
USA
540/544-7333
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